The rapid proliferation of wireless devices is leading to exponential growth in data rates. At existing frequencies, small-cell technology is being explored for meeting this challenge by increasing the spatial re-use of the limited spectrum. Higher frequencies above 6 gigahertz (GHz), including millimeter-wave frequencies (30-300 GHz), are also being explored for addressing the spectrum crunch.
Localization based on wireless channel signatures has a wide range of applications. Wireless channel signatures become richer and more informative at higher frequencies and offer new possibilities for localization. Existing techniques typically use information provided by a line-of-sight (LoS) path, including an angle of arrival, a time difference of arrival, or a received signal strength. However, LoS propagation is not always guaranteed in a real world environment.